From patchwork Tue Oct 12 00:00:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 12551165 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 884F1C433EF for ; Tue, 12 Oct 2021 00:06:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B2BD61038 for ; Tue, 12 Oct 2021 00:06:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234937AbhJLAIa (ORCPT ); Mon, 11 Oct 2021 20:08:30 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:51264 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230213AbhJLAIY (ORCPT ); Mon, 11 Oct 2021 20:08:24 -0400 Message-ID: <20211011223610.889700153@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1633997180; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=5zH7sbOyJ/0kgGAfW88cQB0QECVGl/W35IgTXJyPvBg=; b=yUcSh3MYIq0/7iFpfPM4FaAinzNFuVgaCMr9wLWcU5RyjpGG/sNBpiWC1v22eSmzgbWte6 dW8T74/U+seclD147jdmWavg55483CFSMNGJJQyKRjV/hApBaFnq/9yBn6UTukdw60ZOQL 1VkrMZKFZXjAi8GFhiaF1k9WBGvoLQlUUZWvbJ6l/H8s6CXhrtfOjWdM8Y7Cq/YWjZc/pe V0to9aoj64QiH+rc4pt0iDOZ3mtiMlMmsvryqyi0B1UKZ7UdWEWMeMABS+utzkRVXcvW5u uv9N3IRmcUADSCqnRSrGumKuqqNWf8AxULdeVZljsl5Ydd0MOGyEqfLQiKfi8A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1633997180; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=5zH7sbOyJ/0kgGAfW88cQB0QECVGl/W35IgTXJyPvBg=; b=KHHMyZkgmfd64Vy2mRUZzvDmgdCsvMDRsIZaHRfiOLdTUnybKABW8mfMVA/GV1m64QfylN d5sqm3EoZXmSxMAA== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, "Chang S. Bae" , Dave Hansen , Arjan van de Ven , kvm@vger.kernel.org, Paolo Bonzini Subject: [patch 10/31] x86/fpu: Cleanup xstate xcomp_bv initialization References: <20211011215813.558681373@linutronix.de> MIME-Version: 1.0 Date: Tue, 12 Oct 2021 02:00:13 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org No point in having this duplicated all over the place with needlessly different defines. Provide a proper initialization function which initializes user buffers properly and make KVM use it. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/fpu/internal.h | 4 +++- arch/x86/kernel/fpu/core.c | 35 +++++++++++++++++++---------------- arch/x86/kernel/fpu/init.c | 6 +++--- arch/x86/kernel/fpu/xstate.c | 8 +++----- arch/x86/kernel/fpu/xstate.h | 18 ++++++++++++++++++ arch/x86/kvm/x86.c | 11 +++-------- 6 files changed, 49 insertions(+), 33 deletions(-) --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -80,7 +80,9 @@ static __always_inline __pure bool use_f extern union fpregs_state init_fpstate; -extern void fpstate_init(union fpregs_state *state); +extern void fpstate_init_user(union fpregs_state *state); +extern void fpu_init_fpstate_user(struct fpu *fpu); + #ifdef CONFIG_MATH_EMULATION extern void fpstate_init_soft(struct swregs_state *soft); #else --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -16,6 +16,8 @@ #include #include +#include "xstate.h" + #define CREATE_TRACE_POINTS #include @@ -203,15 +205,6 @@ void fpu_sync_fpstate(struct fpu *fpu) fpregs_unlock(); } -static inline void fpstate_init_xstate(struct xregs_state *xsave) -{ - /* - * XRSTORS requires these bits set in xcomp_bv, or it will - * trigger #GP: - */ - xsave->header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | xfeatures_mask_all; -} - static inline unsigned int init_fpstate_copy_size(void) { if (!use_xsave()) @@ -238,23 +231,33 @@ static inline void fpstate_init_fstate(s fp->fos = 0xffff0000u; } -void fpstate_init(union fpregs_state *state) +/* + * Used in two places: + * 1) Early boot to setup init_fpstate for non XSAVE systems + * 2) fpu_init_fpstate_user() which is invoked from KVM + */ +void fpstate_init_user(union fpregs_state *state) { - if (!static_cpu_has(X86_FEATURE_FPU)) { + if (!cpu_feature_enabled(X86_FEATURE_FPU)) { fpstate_init_soft(&state->soft); return; } - memset(state, 0, fpu_kernel_xstate_size); + xstate_init_xcomp_bv(&state->xsave, xfeatures_mask_uabi()); - if (static_cpu_has(X86_FEATURE_XSAVES)) - fpstate_init_xstate(&state->xsave); - if (static_cpu_has(X86_FEATURE_FXSR)) + if (cpu_feature_enabled(X86_FEATURE_FXSR)) fpstate_init_fxstate(&state->fxsave); else fpstate_init_fstate(&state->fsave); } -EXPORT_SYMBOL_GPL(fpstate_init); + +#if IS_ENABLED(CONFIG_KVM) +void fpu_init_fpstate_user(struct fpu *fpu) +{ + fpstate_init_user(&fpu->state); +} +EXPORT_SYMBOL_GPL(fpu_init_fpstate_user); +#endif /* Clone current's FPU state on fork */ int fpu_clone(struct task_struct *dst, unsigned long clone_flags) --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -121,10 +121,10 @@ static void __init fpu__init_system_mxcs static void __init fpu__init_system_generic(void) { /* - * Set up the legacy init FPU context. (xstate init might overwrite this - * with a more modern format, if the CPU supports it.) + * Set up the legacy init FPU context. Will be updated when the + * CPU supports XSAVE[S]. */ - fpstate_init(&init_fpstate); + fpstate_init_user(&init_fpstate); fpu__init_system_mxcsr(); } --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -15,10 +15,10 @@ #include #include #include -#include #include -#include + +#include "xstate.h" /* * Although we spell it out in here, the Processor Trace @@ -389,9 +389,7 @@ static void __init setup_init_fpu_buf(vo setup_xstate_features(); print_xstate_features(); - if (boot_cpu_has(X86_FEATURE_XSAVES)) - init_fpstate.xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT | - xfeatures_mask_all; + xstate_init_xcomp_bv(&init_fpstate.xsave, xfeatures_mask_all); /* * Init all the features state with header.xfeatures being 0x0 --- /dev/null +++ b/arch/x86/kernel/fpu/xstate.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __X86_KERNEL_FPU_XSTATE_H +#define __X86_KERNEL_FPU_XSTATE_H + +#include +#include + +static inline void xstate_init_xcomp_bv(struct xregs_state *xsave, u64 mask) +{ + /* + * XRSTORS requires these bits set in xcomp_bv, or it will + * trigger #GP: + */ + if (cpu_feature_enabled(X86_FEATURE_XSAVES)) + xsave->header.xcomp_bv = mask | XCOMP_BV_COMPACTED_FORMAT; +} + +#endif --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10612,14 +10612,6 @@ static int sync_regs(struct kvm_vcpu *vc static void fx_init(struct kvm_vcpu *vcpu) { - if (!vcpu->arch.guest_fpu) - return; - - fpstate_init(&vcpu->arch.guest_fpu->state); - if (boot_cpu_has(X86_FEATURE_XSAVES)) - vcpu->arch.guest_fpu->state.xsave.header.xcomp_bv = - host_xcr0 | XSTATE_COMPACTION_ENABLED; - /* * Ensure guest xcr0 is valid for loading */ @@ -10704,6 +10696,9 @@ int kvm_arch_vcpu_create(struct kvm_vcpu pr_err("kvm: failed to allocate vcpu's fpu\n"); goto free_user_fpu; } + + fpu_init_fpstate_user(vcpu->arch.user_fpu); + fpu_init_fpstate_user(vcpu->arch.guest_fpu); fx_init(vcpu); vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);